Tension-compression tester machine



Se t. 2, 1969 T. F. HELMS TENSION-COMPRESSION TESTER MACHINE 4 Sheets-Sheet 1 Filed Dec. 19. 1966 INVENTOR T H 0 M A S F HELMS I furoanns.

Sept. 2, 1969 1*. F. HE LM$ TENSION-COMPRESSION TESTER MACHINE 4 Sheets-Sheet 2 Filed Dec. 19, 1966 INVENTOR THOMAS F. HELMS BY jdyl W ATTORNEYS Sept. 2, 1969 'r. F. HELMS 3,454,251

- TENSION-COMPRESSION TESTER MACHINE Filed Dec. 19, 1966 4 Sheets-Sheet s FIG.3

4 8 INVENTOR 4 THOMAS F.HELMS J NBS,

Sept. 2, 1969 T. F. HELMS TENSION-COMPRESSION TESTER MACHINE 4 Sheets-Sheet 4 Filed Dec. 19, 1966 INVENTOR THOMAS F- HELMS ATTORNEYS United States Patent 3,464,261 TENSION-COMPRESSION TESTER MACHINE Thomas F. Helms, New Fairfield, Conn., assignor to Idex Corporation, a corporation of Connecticut Filed Dec. 19, 1966, Ser. No. 602,814 Int. Cl. G01n 3/28 US. C]. 73-96 Claims ABSTRACT OF THE DISCLOSURE This invention provides apparatus for testing the separation force required to separate an elongated element from a body. The element may be progressively separated from the body along a predetermined path of separation by the application of force thereto. The apparatus comprises movable fixture means for holding the body, and a carriage movable along a path extending away from the fixture means. The movable carriage having mounted thereon force means which are connectable to the element for applying thereto sufficient force to effect the progressive separations of the element from the body along the predetermined path as the carriage moves away from the fixture means. The fixture means being arranged to move toward the path of separation as the element is being separated from the body.

Background of the invention This invention relates to test apparatus for determining the amount of force required to open a container along a seam, to break open an article along a predetermined line, and to separate an elongated element from a body along a predetermined path thereon.

This invention has particular application to apparatus for testing containers having cemented seams, tear tabs, or tear strips. The containers having cemented seams are not intended to be opened, but may be opened by the application of a sufficient force along the cemented seam. The containers having tear tabs or tear strips are intended to be opened by the separation of the tab or strip from the container along predetermined tear lines. Because such tabs or strips are formed by scoring or otherwise weakening the metal along predetermined tear lines, there is the problem of having the proper amount of strength at the tear lines and to make it easy to open the can while avoiding a loss of the strength necessary to have a can that is rupture proof for normal handling or occasional jarring that can cause cans to burst since they are generally sealed under pressure. The apparatus of this invention provides the means for an immediate and accurate determination whether there is sufficient strength in the containers along the prescribed tear lines for public use.

The apparatus provided by this invention, is further utilized in the testing of various products or articles which have a separable element or material bonded or laminated or attached thereto in some manner along a predetermined line or path. Such articles include containers having taped seams; products having bonded, cemented, or soldered joints; laminated products such as circuit boards; coated products such as insulated wiring; moulded reinforced products such as rubber and fabric belting, or tires; and containers having tear strips of paper, plastic or a thin metal. The apparatus is also utilized to test the action of products, such as shock absorbers, where the movement is in tension and compression.

Summary of the invention According to my invention, an apparatus is provided for testing the separation force required to separate an elongated element from a body of which the element is a part. The element may be progressively separated from the body along a predetermined path of separation by the application of a continuous force thereto. The apparatus mcludes movable fixture means for holding the body of which the element is a part and a carriage movable along a path extending away from the fixture means. Mounted on the carriage are force means which are connectable to the elongated element for applying thereto the separation force required to produce progressive separation of the element from the body along the predetermined path of separation as the carriage moves away from the fixture means. Drive means are provided for moving the carriage along the path away from the fixture means. A second set of drive means are provided which operate in a predetermined relationship with respeet to the first drive means. The second set of drive means are connected to the fixture means for progressively moving the fixture means in the direction of the path of separation as the element is progressively separated from the body along the path of separation. Also, force determining means are provided in association with the force means for determining the separation force required to produce progressive separation of the element in each position along the predetermined path of separation.

The apparatus so described is arranged so the second drive means progressively moves the fixture means in a predetermined relationship with respect to the carriage so that the separation force is continuously applied by the force means at a constant angle to the path of separation as the element is being progressively separated from the body along the predetermined path of separation.

In another embodiment of my invention, an apparatus is provided for testing the separation force required to separate an elongated element from a body of which the element is a part and which element may be progressively separated from the body along a predetermined path of separation by the application of a continuous force thereto. The apparatus includes a base having an offset, elongated carriage support beam. Positioned relative to the support beam is a carriage movable longitudinally thereof and arranged to move away from the body along a prescribed path laterally spaced from the support beam. Mounted on the carriage are force application means which are connectable to the elongated element for applying thereto the separation force required to produce progressive separation of the element from the body along the predetermined path of separation as the carriage moves away from the body. Movable fixture means are provided for holding the body as the element is progressively separated therefrom along the predetermined path of separation by the force means as the carriage moves away from the body. Drive means are provided for moving the carriage along the prescribed path away from the body. A second set of drive means are provided which operate in a predetermined relationship with respect to the first drive means. The second set of drive means are connected to the fixture means for progressively moving the fixture means in the path of the separation as the element is progressively separated from the body along the path of separation. Also, force determining means are provided in associationwith the force means for determining the separation force required to produce the sepa ration of the element at each position along the predetermined path of separation.

The apparatus as described in this embodiment of my invention, is arranged so the second drive means progressively moves the fixture means in a predetermined relationship with respect to the carriage so that the separation force is continuously applied by the force means at a constant angle to the path of separation as the element is being progressively separated from the body along the predetermined path of separation.

In addition, my test apparatus may include follower means to indicate the distance the fixture means moves. The follower means are engaged with the fixture means in a manner to move a distance proportional to that of the fixture means. The distance which the fixture means moves corresponds to the length of the predetermined path of separation along which the element is progressively separated from the body. A recording device may be interconnected with my apparatus for recording the separation force required to progressively separate the element from the body along the predetermined path of separation, and the corresponding progressive positions along the predetermined path at which the separation force is applied. Transmitting means may also be provided for continuously transmitting the separation force data, and the corresponding progressive positions of application of the force respectively from the force determining means and the follower means to the recording device. The force determining means includes a force gauge, transducing means for converting the amount of force determined by said force means to a corresponding voltage to be transmitted by the transmitting means to the recording device. The carriage and the fixture means are arranged to move a distance at least equal to the length of the predetermined path of separation.

In one embodiment of the apparatus of this invention, the fixture means is arranged to rotate the body with respect to the carriage so that the separation force is continuously applied by the force means at a constant angle to the path of separation as the element is being progressively separated from the body along the predetermined path of separation. In another embodiment of the test apparatus of this invention, the fixture means is arranged to move the body in a predetermined linear path with respect to the carriage so that the separation force is continuously applied by the force means at a constant angle to the path of separation as the element is being progressively separated from the body along the predetermined path of separation. In a further embodiment of the test apparatus of this invention, the fixture means includes a housing to hold the body under predetermined conditions as force is applied thereto.

Description of the drawings With reference to the accompanying drawings, I shall described the preferred embodiments of my invention. In the drawings:

FIG. 1 is a front view of a selected form of my apparatus;

FIG. 2 is a side view of the selected form of my apparatus of FIG. 1;

FIG. 3 is an enlarged partial sectional view of the force carriage and respective parts of the apparatus engaged therewith;

FIG. 4 is an enlarged side view of one embodiment of the sample holding fixture of my apparatus;

FIG. 5 is an enlarged plan view of the embodiment of the sample holding fixture of FIG. 4;

FIG. 6 is a perspective view of a rotating sample holding fixture embodiment of my apparatus;

FIG. 7 is a perspective view of a linear driven sample holding fixture embodiment of my apparatus; and

FIG. 8 is a perspective view of a pressure sample holding fixture embodiment of my apparatus.

Referrnig to FIGS. 1 and 2, my apparatus in its general arrangement comprises a base plate 10 having an elongated offset carriage support beam 12 and a force carriage 14 which may be movably mounted on a pair of guide ways 16. The force carriage 14 is movably mounted longitudinally relative to the elongated support beam 12 and arranged to move linearly and vertically along the guide ways 16, which, as shown, are parallel to but at rally spaced from the ofis t e o g ed support beam 12. The main part of the force carriage 14, a cross head 15, may have force determining means mounted thereon, such as a force gauge 24. There may be force means suspended from the force gauge 24, such as a hook member 17 by a chain 19. As shown, the hook member 17 is connected to an elongated element E which is a part of a body or sample S. Thus, a force is applied to the sample S to be tested by the chain 19 through the hook 17 to eifect the progressive separation of element E from the sample S as the carriage 14 moves away from the sample S on the guide ways 16.

Movable fixture means 18 are provided for holding the sample S as the element E is progressively separated therefrom along a predetermined path of separation (not shown) by the hook member 17 and chain 19, as the carriage 14 moves away from the fixture means 18. The fixture means 18 is arranged to progressively move in the direction of the predetermined path of separation as the element E is progressively separated from the sample S along the path of separation. Drive means such as a lead screw 20 turned in a conventional manner by a motor (not shown) in the housing 22, are provided for controllably moving the force carriage 14 to apply force by means of the chain 19 and hook 17, to the article S held by the fixture 18. The force gauge 24 is mounted on the force carriage 14 for determining the amount of force applied to the article S throughout the path of separation.

A chain drive assembly is engaged with both the carriage 14 and the fixture 18 to move the fixture 18 in relation to the movement of the force carriage 14. The chain drive assembly (FIG. 2) includes an upper idler pulley 26, a drive chain 28 engaged with the force carriage 14, and a fixture drive sprocket 30 which is connected to the sample holding fixture 18 by a main shaft 32. The chain drive assembly progressively moves the fixture means 18 in the direction of the path of separation as the element E is progressively separated from the sample S along the path of separation. The fixture means 18 is moved in a predetermined relationship with respect to the carriage 14 so that the separation force is continuously applied (by the hook 17 and chain 19 suspended from the carriage 14) at a constant angle to the path of separation as the element E is being progressively separated from the sample S along the path of separation.

'It is advantageous to have the fixture 18 driven to eliminate any errors due to the stick-slip elfect induced by friction, inertia and imbalance. That is, if the fixture 18 is arranged to move freely, as the progressive separation begins of the element E from the sample S, and after the static friction and inertia are overcome, there is a tendency for the element E to be separated at an uneven rate. Thus, the force required for separating the element E from the sample S throughout the path of separation cannot be accurately determined. However, by controllably moving the fixture 18, the progressive separation of the element E from the sample S along the path of separation is steady and even. Thereby, the proper conditions are provided for accurately determining the force required to progressively separate the element E from the sample S throughout the path of separation.

Engaged with the fixture 18 and the chain drive assembly is a follower means to indicate distance the fixture 18 moves. The following means (FIGS. 2 and 5) includes a small pulley 34 and a gear belt 36 which extends from a larger pulley 38 (FIGS. 4 and 5) connected to the fixture drive sprocket 30 of the chain drive assembly. The pulley 38 is connected to the fixture 18 by the main shaft 32. With this arrangement, the following means move a distance proportional to that of the fixture 18.

The distance which the fixture 18 moves, as does the carriage 14, is equal to the length of the predetermined path of separation along which the element E is progressively separated from the sample S, and along which the separation force is applied to effect the progressive separa: tion of the element E. Thus, the progressive movement of the following eans corresponds to the progressive positions along the path of separation at which the separation force is applied to the sample S. These progressive positions of application of force are indicated by the progressive movement of the small pulley 34 and transmitted through a flexible shaft 40 to a recorder 42. The recorder 42 may be of any known type and is engaged with the force gauge 24 and the follower means to record respectively the amount of force applied to the sample and the corresponding positions at which the separation force is progressively applied along the path of separation on the sample S. The force data is transmitted to the recorder 42 by transmitting means such as a transducer 60 connected to the force gauge 24 and a signal cable 62 (FIG. 2) extended from the transducer 60 and connected to the recorder 42 by electrical wires (not shown).

In the preferred construction illustrated, FIGS. 1-3, the force carriage 14 is slidably mounted on the pair of guide ways 16 extended upward from the base plate parallel but laterally spaced apart from the elongated support beam 12, FIG. 2. The movement of the carriage 14 is limited by upper and lower shaft blocks 66 and 68 at the opposite ends of the guide ways 16. The hook member 17 at the end of the chain 19, is connected to the element E of the sample S to apply a separation force to the element B when the force carriage 14 is moved away from the fixture 18. The chain assembly which moves the fixture 18 according to the movement of the force carriage 14 is engaged with and running through the carriage 14 and is also engaged with the sample holding fixture 18 by means of the chain 28 around the sprocket through which the shaft 32 is connected to the fixture 18. Thus, the fixture 18 holding the sample S is moved in relation to the carriage 14 so that the separation force is continuously applied by the hook 17 and chain 19 at a constant angle to the path of separation as the element E is progressively separated from the sample S.

The chain 28 is engaged with the force carriage 14 at either position A or B, (FIG. 1) at one time by the drive chain clutch 29 for alternate movement of the fixture 18. This arrangement is for moving the fixture 18 in either a clockwise or counterclockwise movement, depending on the direction in which the element E is to be separated from the sample S. The handles 31 are moved to secure the chain in the respective positions, A and B, by a spring loaded pin 27 arrangement (FIG. 3). When the fixture means is to be moved in a clockwise fashion, for example, the chain is secured at position A by pressing the right handle 31. As the force carriage 14 is moved upward the fixture means 18 rotates in a clockwise manner.

The means for controllably moving the carriage 14 may be any suitable means such as the lead screw 20 engaged with the force carriage 14. The lead screw 20 can be turned so as to vertically move the carriage 14 either upwardly or downwardly at a predetermined speed by the motor in the housing 22, or other mechanical means. The lead screw 20 may be engaged with the force carriage as shown in FIG. 3, by a half-nut arrangement which includes a half nut 56, a bolt 57, a half-nut spring 58, and a release lever 59. This arrangement allows the force 14 to be moved easily in an upward or downward motion as desired.

The force carriage 14 may be arranged with the fixture 18 to provide a compression test on the sample S rather than a tension test as described hereinabove. In a compression test, the force carriage 14 will be moved downward and the fixture 18 would hold and move the sample S so as to allow the application of a force to the sample S along a predetermined path thereon. The force carriage 14, instead of having a chain 19 with a hook 17 suspended therefrom, would have a rod or shaft or some force member extended therefrom. When the carriage 14 is moved downward toward the sample S, the force member would be progressively pressed against the sample S along the predetermined path and apply the necessary force to break open the sample S along the predetermined path thereon. In this arrangement the necessary force needed to puncture or compress a container would be indicated by a force gauge 24. Otherwise, the apparatus in a compression test would operate in much the same way as described hereinabove for a tension test on a sample S.

The motor in housing 22 may have a fixed or variable speed. A variable speed motor may be advantageous in that the apparatus can be operated at various speeds for the many types of samples that may be tested. The motor may be attached to the lead screw 22 by any suitable and conventional means such as by gears or a coupling setup. The motor should be such that it can reverse its direction so that the lead screw 20 may be turned accordingly. This is to provide for the vertical movement in either direction of the force carriage 14 for applying either a force of tension or compression on the sample.

Referring to FIGS. 4 and 5, one embodiment of the sample holding fixture 18 is shown in relation to joining parts of the test apparatus. The sample is positioned on the fixture 18 under a finger 44 and is secured between a rubber ring 46 and another ring 48. A metal compression member 50, presses the rubber ring 46 against the sample ring 48 when the fixture 18 is closed by a clamp 52 to secure the sample during movement of the fixture 18 and when force is applied to the sample by the force carriage 14. The fixture 18 rotates on the shaft 32 connected to the sprocket 30 of the chain drive assembly which is moved by the movement of the force carriage 14. By this interconnection, the fixture 18, when holding the sample, moves so that the separation force is continuously applied by the chain 19 and hook 17, at a constant angle to the path of separation on the sample S as the element E is being separated therefrom. The separation being etlected as the carriage 14 moves away from the fixture 18.

The amount of force required to separate the element E from the sample S may be determined by any suitable means known in the art. In the present embodiment, the force gauge 24, FIGS. 1 and 2, is used to determine the separation force. A dial 25, may be placed on the front of gauge 24 to indicate the force required to separate the element E from the sample S. According to this embodiment of my invention, the amount of force required to affect the separation of the element E, relates to the linear displacement of the force gauge 24. The linear displacement is transmitted in a voltage output to the recorder 42 by the transducer 60 mounted on an adjustable bracket 64 (FIGS. 1 and 2) through the signal cable 62 and electrical wiring (not shown) extended therefrom. The voltage output is in ratio to the linear displacement of the force gauge 24. For example, for the displacement of the force gauge of 0.001 inch, a voltage output of 1.0 millivolt is transmitted to the recorder 42. This data, the voltage output, is converted into force units by the recorder 42 and recorded on a chart in a known manner to correspond with the position of application of force to the sample on the predetermined path thereon.

The position of application of the separation force is indicated by the drive being transmitted by the flexible shaft 40 extended from the lower recorder pulley 34. The lower pulley 34 moves with the fixture 18 by means of the belt 36 moved by the upper pulley 38 which is connected to the fixture 18 by the shaft 32, FIG. 5. The distance along the path of separation to which the continuous force is applied, is followed by the lower pulley 34. Thus, the progressive positions of application of the continuous separation force along the predetermined path of separation on the sample S are indicated by the corresponding distance the lower pulley 34 has moved. These progressive positions, at which the separation force is applied, are then continuously transmitted by the flexible shaft 40 to the recorder 42 to be recorded on the chart. The drive of the shaft 40 causes the chart of the recorder 42, to move a distance proportionate to the length of the path 7 of separation along which the element E is separated from the sample S. Although it is not necessary, it is preferred to have the chart move a distance equal to that of the length of the path of separation. By having the chart move a distance equal to the length of the path of separation on the sample, a direct comparison can be made between the sample and the recorded force data on the chart immediately after the test.

The over all operation of the test apptratus may be operated and controlled by electrical control means such as a control unit 70 shown in FIGS. 1 and 2. The operation of the apparatus may be controlled by buttons or other well known touch control means.

The versatility of this invention to test various type samples in shown in FIGS. 6, 7, and 8 by the different different embodiments of the sample holding fixture. These embodiments may be used for the various types of samples and conditions as may be desired. In FIG. 6, a rotating fixture 74 is shown. The fixture 74 rotates a sample 76 so that the separation force applied by the hook 17 and chain 19 is at a constant angle to the path of separation as the element E is being progressively separated from the sample 76 along the separation path. The hook 17 attached to element E is suspended by the chain 19 from the force gauge 24 mounted on the force carriage 14, see FIGS. 1 and 2.

In FIG. 7, a linear drive fixture 78 is shown which moves a sample 80 in a linear path so that the force applied by the hook 17 and chain 19 is at a constant angle to the path of separation as the element E is being progressively separated from the sample 80 along the separation path. The fixture 78 can be driven in either direction by use of the clutch 31 (FIGS. 1 and 2). Here, the fixture 78 is shown moving to the left, while force is being applied to the sample 80 by the hook member 17 attached to chain 19.

In FIG. 8, a fixture 82 is shown which holds one side of the sample 84 under desired conditions as force is applied to the opposite side thereof by the hook member 17 connected to the element E. The sample 84 is sealed on top of a pressure chamber 86, and air is admitted into the chamber 86 through an inlet 88. By applying pressure to one side of the sample 84, it is held under conditions similar to those as when in use, such as the top of a beer can. The sample may be placed or held under other conditions as desired, such as a vacuum.

It is to be noted, in the opeartion of the test apparatus that the fixture 18 should move in relation to the carriage 14, i.e., the same rate and distance. This provides for a constant angle of force applied by the force means, chain 19 and hook 17, to the path of separation along which the element E is progressively separated from the sample S. Although the force angle may be at various degrees in accordance with the type of sample being tested, advantageous results are obtained by having the force angle at ninety degrees.

The terms and expressions which I have employed are used in a descriptive and not a limiting sense, and I have no intention of excluding equivalents of the invention described and claimed.

I claim:

1. Apparatus for testing the separation force required to separate an elongated element from a body of which the element is a part, and which element may be progressively separated from the body along a predetermined path of separation by the application of a continuous force thereto, said apparatus comprising movable fixture means for holding said body of which said element is a part, a force carriage movable in either direction on a pair of parallel guideways along a path extending away from said fixture means, force means mounted on said carriage and connectable to said elongated element for applying thereto the separation force required to produce progressive separation of said element from said body along said predetermined separation path as said carriage moves away from said fixture means, first drive means for moving said carriage on said guideways along said path away from said fixture means, second drive means operating in a predetermined relationship with respect to said first drive means, said second drive means being connected to said movable fixture means for progressively moving said fixture means in either diretcion along said path of separation as said element is progresively separated from said body along said path of separation, and force determining means on said force means for determining the separation force required to produce progressive separation of said element at each position along said predetermined path of separation.

2. Apparatus for testing the separation force as claimed in claim 1, wherein said second drive means progressively moves said fixture means in a predetermined relationship with respect to said carriage so that the separation force is continuously applied by said force means at a constant angle to said path of separation as said element is being progressively separated from said body along said predetermined path of separation.

3. An apparatus for testing the separation force required to separate an elongated element from a body of which the element is a part and which element may be progressively separated from the body along a predetermined path of separation by. the application of a continuous force thereto, said apparatus comprising:

(a) a base having an offset, elongated carriage support beam with a pair of parallel carriage guideways;

(b) a carriage movable longitudinally of and relative to said support beam on said guideways, and arranged to move away from said body along the prescribed path of said guideways laterally spaced from said support beam;

(c) force application means mounted on said carriage and connectable to said elongated element for applying thereto the separation force required to produce progressive separation of said element from said body along said predetermined path of separation as said carriage moves away from said body;

(d) movable fixture means attached to said base for holding said body as said element is progresively separated therefrom along said predetermined path of separation by the force means as said carriage moves away from said body;

(e) first drive means for moving said carriage on said guideways along said prescribed path away from said body;

(f) second drive means operating in a predetermined relationship with respect to said first drive means, said second drive means being connected to said movable fixture means for progressively moving said fixture means in either direction of said path of separation as said element is progressively separated from said body along said path of separation; and

(g) force determining means as part of said force means for determining the separation force required to produce progressive separation of said element at each position along said predetermined path of separation.

4. Apparatus for testing the separation force as claimed in claim 3, wherein said second drive means progressively moves said fixture means in a predetermined relationship with respect to said carriage so that the separation force is continuously applied by said force means at a constant angle to said path of separation as said element is being progressively separated from said body along said predetermined path of separation.

5. Apparatus for testing the separation force as claimed in claims 3 or 4, which further includes follower means to indicate the distance said fixture means moves, said follower means are engaged with said fixture means in a manner to move a distance which is proportional to that of said fixture means, said distance which said fixture means moves corresponds to the length of said predetermined path of separation along which said element is progressively separated from said body.

6. Apparatus for testing the separation force as claimed in any one of claims 3 to 5, wherein there are included:

(a) a recording device for recording the separation force required to progressively separate said element from said body along said predetermined path of separation, and the corresponding progresive positions along said predetermined path at which said force is applied; and

(b) transmitting means for continuously transmitting the separation force data, and corresponding progressive positions of application of said force respectively from said force determining means and said follower means to said recording device.

7. Apparatus for testing the separation force as claimed in claim 6, wherein said force determining means comprises a force gauge, transducing means for converting the amount of force determined by said force gauge to a corresponding voltage to be transmitted by said transmitting means to said recording device.

8. Apparatus for testing the separation force as claimed in claim 3, wherein said carriage is arranged to move a distance at least equal to the length of said predetermined path of separation and said fixture means is constructed to move a distance proportional to the length of said path and to be adjustable so that the movable distance may be set by the operator as desired.

9. Apparatus for testing the separation force as claimed in claims 3 or 4, wherein said fixture means is arranged to move said body in a predetermined path with respect to said carriage so that the separation force is continuously applied by said force means at a constant angle to the predetermined path of separation as said element is being progressively separated from said body along said path of separation.

10. An apparatus for testing a sample, where the testing of such sample requires the application of force thereto progressively along a predetermined path thereon, said apparatus comprising movable fixture means for holding said sample during the application of force thereto, a force carriage movable reciprocally on guideway means to define a path extending from said fixture means, force means mounted on said carriage and adapted for applying a force to said sample along said predetermined path thereon means for applying a moving force to said carriage along the path extending form said fixture means, force determining means associated with said force means for determining the amount of force applied to said sample throughout said predetermined path thereon, recording means responsive to both the movement of said fixture means and the force determining means to record the force applied to the sample at progressive positions throughout said predetermined path thereon and means for driving said movable fixture means by the movement of said carriage.

References Cited UNITED STATES PATENTS 2,751,784 6/1956 Gershberg 7396 X 3,019,644 2/1962 Manciri 7396 X 3,318,143 5/1967 Helms 7396 3,319,462 5/1967 Ostrowski 73-96 3,037,379 6/1962 Wagner et al. 73150 X RICHARD C. QUEISSER, Primary Examiner J. W. MYRACLE, Assistant Examiner 

